This video was recently submitted to APOD; the submitter, professional photographer and Interpretive Services Supervisor at the Hopewell Rocks (in New Brunswick, Canada) Kevin Snair asked what the mysterious greenish something appearing about 0:24 in the video -- corresponding to about 2:00 AM -- is:

I set up my camera on Sunday night of the perseids and captured a time lapse video from 9:30 pm to 3:00 am. Somewhere around 2:00, some strange greenish clouds/mist/fog appeared in the shots. They were not readily apparent to the naked eye but the camera picked them up. Do you have any idea what they may be?

And right now, the official APOD answer is no. Please help; thank you!

The light seems to travel toward the camera; at 0:27 and 0:28, the foreground gets lighter as the green comes closer to the camera. So there may be something in the sky (rocket? lights of some sort?) that are traveling out of view of the camera, toward it, and lighting up the clouds. Or maybe it's a reflection, as you suggest, Stephen; the foreground lighting and what is in the sky are close in color.

Here is more information from the photographer in response to my questions:

The camera was facing approximately South East.
It was shot on the evening of August 11th leading into the morning of the 12th. No aurora were forecast in South-East New Brunswick that evening.
There is a small airport 25 miles to the North but little or no air traffic going to it that evening. We do see some air traffic going through the shot from middle right to upper left but they were very high and not landing in our province.
The air temp was 12 degrees Celsius (54 degrees Fahrenheit)
There was no unusual weather that night to my knowledge.

The video was taken as a time lapse. Each photo was 30 seconds long with the camera at a high ISO. I took one photo every 40 seconds to create the video. The green clouds in question started to show in the photos at around 2:01 am and ended by 2:58 am.

I wrote to him a bit ago to ask about the foreground lighting; wish I'd seen your post, Stephen, before I sent that off! I've also asked whether he could provide two or three stills.

Looks like very high clouds and light from the ground illuminating them. Probably sodum vapor lamps which have a green spectral line and is very commonly used in street lighting. Just after the green glow there are clouds moving at a right angle to the green "clouds" motion so I'm thinking this is some sort of front cloud formation at very high levels that form and then are distroyed by the front passage. They would be green due to the preponderance of street lighting at that time of day (early morning when most home and auto lights are off)
We could check to see if the city directly in front of the camera uses sodum vapor lights and the weather to see if there was some sort of front passage. I have not had the opportunity to check those facts.
v/r
William Roosa

Geckos, geckos! I should note that when Stephen suggested artificial light source reflecting off the water I couldn't think of any convincing argument against it. I'm sitting 50/50 on the possibility of air glow vs. water reflection. I do think the possibility of algae contributing any detectable amount of light to the reflection is extremely small, though.

geckzilla wrote:
I should note that when Stephen suggested artificial light source reflecting off the water I couldn't think of any convincing argument against it. I'm sitting 50/50 on the possibility of air glow vs. water reflection. I do think the possibility of algae contributing any detectable amount of light to the reflection is extremely small, though.

The artificial light source isn't pointed at the sea...
it's pointed at the land & all those green trees

You can even see the reflected green tree light
on the Hopewell Rocks facing the beach in the APOD.

geckzilla wrote:
I should note that when Stephen suggested artificial light source reflecting off the water I couldn't think of any convincing argument against it. I'm sitting 50/50 on the possibility of air glow vs. water reflection. I do think the possibility of algae contributing any detectable amount of light to the reflection is extremely small, though.

The artificial light source isn't pointed at the sea...
it's pointed at the land & all those green trees

You can even see the reflected green tree light
on the Hopewell Rocks facing the beach in the APOD.

I don't understand what you mean. It looks kind of like the photographer may have set up a light on the ground there behind one of the rocks as well as behind the camera. I don't know for sure, though.

geckzilla wrote:
I don't understand what you mean. It looks kind of like the photographer may have set up a light on the ground there behind one of the rocks as well as behind the camera. I don't know for sure, though.

The Hopewell Rocks are lit indirectly by a floodlight facing at & reflecting off of the beach.

The morning mist is lit indirectly by that same floodlight facing at & reflecting off of a plethora of trees just above the beach.

geckzilla wrote:
I don't understand what you mean. It looks kind of like the photographer may have set up a light on the ground there behind one of the rocks as well as behind the camera. I don't know for sure, though.

The Hopewell Rocks are lit indirectly by a floodlight facing at & reflecting off of the beach.

The morning mist is lit indirectly by that same floodlight facing at & reflecting off of a plethora of trees just above the beach.

How would you explain the lack of green something before the tide comes in, then? Or are you just suggesting the green color is due to the light being first filtered through the plant life?

I see the green tint in the picture right from the start. Only when the high altitude clouds come in it is enhanced. Notice it stays in one place, and the movement is the clouds alone. Could be an artifact of the lens reflecting the forground. The photographer should simply repeat the movie just as before with the same lighting and equipment.

From the angle (regarding the rocks and the shore) it looks like the pics were taken pointing almost due south. Indeed it looks like a rare northern lights display as seen from here in New Brunswick, but must be caused by some other means. Sure does seem to coincide with the incoming tide and the pre-existing green glow reflecting towards the sky/clouds.

First time I write here ! I didnt read all the posts but so far, it looks alot like something I've seen more than 10 years ago. I have no idea what it can be (cosmic winds ?) but unlike your situation, I could see it with naked eyes. That kind of waves filled the entire sky and appeared around 23h00. The light waves shown an incredibly fast propagation. The location although was higher than NB : L'Annonciation in Quebec. It was about end of august.

You know, you should make a test of IR and ultraviolet with your MarkII by pointing a remote control or blacklight (caution ! Take it at least 5 feets from it) towards the lens and take a snapshot to see how much it can capture of it (look for how much overexposed). My guess is that your CMOS goes slightly outside visible spectrum.If so, you will capture more than meet the eye.

It is very intriguing and push me to finish modifying an old Canon expressly for that. desjardm5@gmail.com